I've got a l98 Iroc. I've got 28lb LS1 injectors (60k miles on them) and a new Delphi fuel pump, MSD coil, new ac delco cap, rotor, and new wires. The car runs great it just seems to crank a little longer than I'd think it would. It cranks for probably 3 or 4 seconds before it starts. Would this be normal?

 

Can you hear the fuel pump prime when you turn 1st the key on?
If not you are waiting for the oil pressure switch to close when oil pressure comes up during cranking
and turn the pump on
Faulty pump relay maybe?

 

I hope you have a custom tune for those big injectors?

 

Where is the fuel pump relay located? Mine does the same thing. Getting ready for rearend swap so might replace fuel pump at the same time just in case.

 

Nope no tune. Car doesn't run rich at all. Plugs were perfect when I put my headers on today. I read around online before I ever attempted to do it and found where they were talking about that a LS1 injector is rated at like 58 psi where we're rated at 45 so the 28's with the lower pressure made it equal out if that makes sense.

 

Well I replaced the relay and the same thing. Cranks over about 4 times and then starts. I can't tell if my fuel pump is priming because my secondary fan comes on with the key for some reason. I'm going to unplug my fans and cycle to key to see. If it is priming is it possible its the ignition module not telling the injectors to squirt until it starts cranking? I'm just guessing.

 

how old is your starter?

 

mine turns on at about .5 seconds. i say new spark plugs n wires.

 

The starter is new. It cranks fine. Very fast. It has new coil, cap, rotor, wires, and plugs.

 

How are your battery cables. Also, make sure your grounds behind your heads are connected well.

 

fuel filter good?? hows the psi from fuel pump? are injectors clean?

 

The engine has to be cranking over before the dist will generate the signal to the computer in order for it to pulse the injectors.
otherwise engine would just fill up with fuel if injectors fired when key turned on
But when the injectors are pulsed there needs to be pressure in the fuel rail which comes from the pump priming them
or waiting until the OP switch closes to run the pump

 

Fuel pump is a new delphi, fuel filter is new, injectors are out of my 02 WS6 that had around 60k on it and I never had any problems with it. How do I know if they're clean? I've ran some seafoam through it. Other than the relay what controls the priming? I had the grounds off the back of the head the other day when I put headers on so they're definately on and tight.

 

hmm,well to start just get a noid light and see if all of them are getting the signal from the ECM. then after that. connect the wires and the injector to the rail but dont connect the rail to the inake. crank the car and see if gas is going through all of them. maybe junk is in one of them. i tested mine out by connecting them like i said but i put a plastic baggy around every single one and cranked it and checked. only some where getting fuel through so i knew it was time for new ones. now car statrs marvelous.

 

Personally I don't think you have a major problem, is not as if you have to crank it for 20 sec in order for it to fire

All the other comments ( pump / filter / injectors/ etc) only relate to if you had a hard start ,
no start or bad running problem which you don't mention

 

This is true, none the less the car starts. but obviously you want it to start right on the dot right?

 

I'm always letting off the key before the car starts. If i'm moving around or something with the door shut and not hearing it crank you can't tell when it starts to hit and I figured it would be something simple like a relay that was a common problem or maybe even normal for an older fuel injection system.

 

more than likely,starting problems are usually related to something in the starting system, bad battery cables, short spot in the starter,etc, but could also be a clogged fuel filter too

 

He states it cranks over fine ( with a new starter ) just takes time to fire up ; which means ; NO FUEL instantly available

Clogged filter would show up more when the engine is running and requiring more fuel (WOT ) than at idle

 

I unplugged the fans and listened. I cycled the key a few times and I heard it prime the first time but it wouldn't again. I would assume thats normal.

 

I believe thats right. How long has this been doing this?Did it start right with the stock injectors?

 

im thinking the injectors are just not in very good shape, either that or the lines are a bit dirty. what gapp size are your spark plugs?

 

Pump only runs for 2 sec key on to prime the rails ; then stops until engine is cranked over
Put a pressure gauge on the test point and see if prime pressure holds in the ails.
If reg is leaking down ( or one way valve in tank ) then you will have little / no pressure for the injectors until the engine is cranked over

 

Wild guesses
As noted ,any of those problems would show up more once engine is running and requires more fuel;not on start up
and OP doesn't state any problems once engine has started up

 

Its always took a little longer to start. About two days after I got the car it started missing at idle when hot and didn't have any power while driving. The injectors completely cured the problem. Then I drove it about 45 minutes away and the fuel pump went out. You could start the car and listen at the tank and the pump would quit every 30 seconds and the car die right after. I let it cool for an hour and it got me home. Plugs are new AC declos gapped on 35. What exactly is the one way valve in the tank? When he put the pump in he put a piece of fuel injection hose in place of the pulsator? Once the car is running it runs perfect no problems at all. Just cranks a little longer.

 

I had some of the same symptoms you describe on my 89.
It turned out the oil pressure switch was bad, also I've heard that a bad or weak fuel pressure regulator will cause a hard start or long crank time condition.